Carrots or french fries. How are you feeling about this choice And be honest really which would you rather eat? That’s what I thought. Humans love fat and carbohydrates. Why? Because they have a lot of energy in them and energy is what we need to do all of the stuff that we humans do. But we’re omnivores, we can get our energy from meat, grains, vegetables, nuts, tubers, fruit we are extremely versatile animal compared to like a cow which is pretty much stuck eating grass or a lion which has no business eating anything other than raw meat. So we can get calories from a bunch of different kinds of foods Why – at a very basic level do we really just wanna eat fat and carbs? Well, it has a lot to do apparently with our evolutionary history. Let’s start with a member of my extended family: Grandma Australopithecus This pretty lady was a direct ancester of the first member of the Genus Homo. She was different than us in a lot of ways: Her brain was 35% size of ours Her stomach was a lot bigger and her teeth were larger, flatter and duller All of these leads us to the conclusion that australopithecus ate mostly fruits, vegetables and tubers The raw fruits and vegetables especially before the agricultural revolution weren’t very high on calories And if that’s all you’re eating it takes a big, patient digestive system to process that So your body is working really hard all day to squeeze every last calorie out of your not very energy rich food, something’s gotta give and for australopithecus it meant having you know, kind of a tiny brain ‘Cause brains require lots of calories It wasn’t until australopithecus’ direct decendant Homo Habilus came along, 2 milions years ago (About the time australopithecus went extinct actually) that we’re starting seeing smaller more, efficient guts smaller teeth and a brain about 50% bigger than australopithecus’. These clues coupled with the fact that this is around when Habilus began to control fire, suggests that they were able to cook. And that means they were suddenly able to eat meat without worrying about dying of nasty, festering meat disease And they were suddenly able to unlock all sorts of hidden, delicious energy from the vegetables that are pretty stingy when they’re raw So since then every species in the Genus Homo from Habilus to Homo Sapiens have had larger and larger brains, thanks in part to increasingly high energy diets These huge brains of ours are expensive, and we’ve needed a bunch of fat and calories for them to evolve, not to mention just to maintain them So because our brains are not stupid, they’ve evolved love the living crap out of high energy food And now look at us! We can eat a doughnut hamburger whenever we want to because we’re the kings of the frickin’ earth! And our brains, they’re like: YEAH! In fact some studies have revealed that eating high fat food not only activates our brain’s pleasure centres, it also activates the touch centres So our brains respond to eating fatty, high calorie foods the same way we respond to hugs from our moms! Literally comfort food! But even though our brains are totally prump the grocery stores are now packed full of sweet, sweet Snicker bars, the rest of our bodies are like: “I’m so tired of dealing with all of this nougat. HELP US!!” Which is why, even though a carrot doesn’t look as good, you should eat it! Your body…will thank you! Thank you for watching this episode of SciShow, if you have any questions or ideas or comments or thoughts for us, please leave them down below Or on Facebook or Twitter and if you wanna continue getting smarter with us, go to youtube.com/SciShow, and subscribe! This episode is brought to you by nutritious things…not by fries! Just to be clear.